This study shows links between Long COVID’s neurological effects, including brain fog and cognitive decline, and brain blood vessel integrity, offering hope for new treatments and diagnostic methods.
https://www.nature.com/articles/s41593-024-01576-9 (open access)
I think in some ways that could work.
I think a better one may be fish living in a tank that suddenly had its filter break (fish being the brain, and the filter being the BBB).